Env Vars with enforcement and typing

config.ts

import * as dotenv from 'dotenv';

dotenv.config();

const VARS = {
  API_TOKEN: 'an API token',
  API_URL: 'a URL for an endpoint',
} as const;

for (const [varname, description] of Object.entries(VARS)) {
  if (typeof process.env[varname] !== 'string') {
    throw new Error(`Please set the env var ${varname} to ${description}`);
  }
}

export const {
  API_TOKEN,
  API_URL,
} = process.env as {
  [k in keyof typeof VARS]: string;
};